Heat pump air conditioning system control method and apparatus, storage medium, and vehicle

Abstract

The present application is applicable to the technical field of automobiles, and provides a heat pump air conditioning system control method and apparatus, a storage medium, and a vehicle. The heat pump air conditioning system control method comprises: acquiring a current exhaust temperature and a current exhaust pressure of a heat pump air conditioning system; determining, among multiple preset temperature levels, a current temperature level to which the current exhaust temperature belongs, and determining, among multiple preset pressure levels, a current pressure level to which the current exhaust pressure belongs; and on the basis of the current temperature level and the current pressure level, adjusting a degree of openness of an electronic expansion valve of the heat pump air conditioning system to a target degree of openness, the target degree of openness being greater than or equal to a first degree of openness. The first degree of openness is obtained on the basis of an optimal exhaust pressure for the heat pump air conditioning system, and the optimal exhaust pressure is related to a refrigerant temperature at an outlet side of an air cooler. Embodiments of the present application help to allow the heat pump air conditioning system to operate in a high energy efficiency range, thereby achieving the purpose of saving energy.

Description

Control method and device of heat pump air conditioning system, storage medium and vehicle

[0001] The present application claims priority from the Chinese patent application No. 202411372019.9 filed with the State Intellectual Property Office on September 29, 2024 and entitled "Control method and device of heat pump air conditioning system, storage medium and vehicle", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the field of automobile technology, and in particular relates to a control method and device of a heat pump air conditioning system, a storage medium and a vehicle. BACKGROUND

[0003] The heat pump air conditioning system is a system driven by electric energy, and the heat pump air conditioning system realizes the functions of refrigeration and heating by using components such as compressors, condensers, electronic expansion valves and evaporators. At present, the heat pump air conditioning system needs to control the opening degree of the electronic expansion valve to control the superheat degree at the outlet of the evaporator or the subcooling degree at the outlet of the condenser, so as to make the whole system run in a stable and efficient interval. However, through actual testing, it is found that some heat pump air conditioning systems cannot necessarily run in the high-efficiency interval under this control mode, which leads to the fact that the system performance cannot be fully exerted. SUMMARY

[0004] The embodiments of the present application provide a control method and device of a heat pump air conditioning system, a storage medium and a vehicle, which can reduce the problem of wear and tear of components caused by excessively high intake air temperature after supercharging.

[0005] The first aspect of the embodiments of the present application provides a control method of a heat pump air conditioning system, comprising: obtaining a current exhaust temperature and a current exhaust pressure of the heat pump air conditioning system; determining a current temperature level to which the current exhaust temperature belongs among a plurality of preset temperature levels, and determining a current pressure level to which the current exhaust pressure belongs among a plurality of preset pressure levels; adjusting the opening degree of an electronic expansion valve of the heat pump air conditioning system to a target opening degree according to the current temperature level and the current pressure level, the target opening degree being greater than or equal to a first opening degree, the first opening degree being obtained according to an optimal exhaust pressure of the heat pump air conditioning system, the optimal exhaust pressure being related to the refrigerant temperature on the outlet side of the air cooler.

[0006] In some embodiments of the present application, the control method of the heat pump air conditioning system further comprises: determining the optimal exhaust pressure according to the refrigerant temperature; determining a control parameter for proportional-integral control of the electronic expansion valve according to the optimal exhaust pressure; and determining the first opening degree according to the control parameter.

[0007] In some embodiments of the present application, the control parameter comprises a feedforward value and a control error of proportional integral control; and the control parameter for proportional integral control of the electronic expansion valve is determined according to the optimal exhaust pressure, comprising: calculating a pressure difference between the current exhaust pressure and the optimal exhaust pressure; calculating a temperature difference between an actual outlet air temperature of the heat pump air conditioning system and a target outlet air temperature of the heat pump air conditioning system; determining the feedforward value according to the ambient temperature and the temperature difference; and determining the control error according to the pressure difference.

[0008] In some embodiments of the present application, the plurality of preset temperature levels comprises a first temperature level, and the plurality of preset pressure levels comprises a first pressure level; and the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to a target opening degree according to the current temperature level and the current pressure level, comprising: if the current temperature level is the first temperature level and the current pressure level is the first pressure level, the opening degree of the electronic expansion valve is adjusted to a first opening degree; and if the current temperature level exceeds the first temperature level or the current pressure level exceeds the first pressure level, a minimum opening degree of the electronic expansion valve is determined according to a current rotating speed of the compressor of the heat pump air conditioning system, and a maximum value between the minimum opening degree and the first opening degree is taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree.

[0009] In some embodiments of the present application, the plurality of preset temperature levels further comprises a second temperature level higher than the first temperature level, and the plurality of preset pressure levels further comprises a second pressure level higher than the first pressure level; and the control method of the heat pump air conditioning system further comprises: if the current temperature level exceeds the second temperature level or the current pressure level exceeds the second pressure level, the compressor is controlled to reduce the rotating speed at a preset reducing rotating speed rate.

[0010] In some embodiments of the present application, the plurality of preset temperature levels further comprises a third temperature level higher than the second temperature level and a fourth temperature level higher than the third temperature level, and the plurality of preset pressure levels further comprises a third pressure level higher than the second pressure level and a fourth pressure level higher than the third pressure level; and the compressor is controlled to reduce the rotating speed at a preset reducing rotating speed rate, comprising: if the current temperature level is the third temperature level or the current pressure level is the third pressure level, the compressor is controlled to reduce the rotating speed at a first reducing rotating speed rate; and if the current temperature level is the fourth temperature level or the current pressure level is the fourth pressure level, the compressor is controlled to reduce the rotating speed at a second reducing rotating speed rate, which is higher than the first reducing rotating speed rate.

[0011] In some embodiments of the present application, the plurality of preset temperature levels includes a fifth temperature level, and the plurality of preset pressure levels includes a fifth pressure level; the control method of the heat pump air conditioning system further includes: when the current temperature level is the fifth temperature level or the current pressure level is the fifth pressure level, controlling the electronic expansion valve according to the maximum opening degree of the electronic expansion valve, and reducing the rotation speed of the compressor to 0.

[0012] The control device of the heat pump air conditioning system provided in the second aspect of the embodiments of the present application includes: an acquisition unit configured to acquire a current exhaust temperature and a current exhaust pressure of the heat pump air conditioning system; a grading unit configured to determine, among a plurality of preset temperature levels, a current temperature level to which the current exhaust temperature belongs, and determine, among a plurality of preset pressure levels, a current pressure level to which the current exhaust pressure belongs; and a control unit configured to adjust an opening degree of an electronic expansion valve of the heat pump air conditioning system to a target opening degree according to the current temperature level and the current pressure level, the target opening degree being greater than or equal to a first opening degree, the first opening degree being obtained according to an optimal exhaust pressure of the heat pump air conditioning system, the optimal exhaust pressure being related to a refrigerant temperature on an outlet side of the air cooler.

[0013] The computer readable storage medium provided in the third aspect of the embodiments of the present application stores a computer program, and the computer program is executed by a processor to implement the steps of the control method of the heat pump air conditioning system.

[0014] The vehicle provided in the fourth aspect of the embodiments of the present application includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the vehicle includes a heat pump air conditioning system, and the processor executes the computer program to implement the steps of the control method of the heat pump air conditioning system.

[0015] The computer program product provided in the fifth aspect of the embodiments of the present application, when executed on a vehicle, causes the vehicle to execute the control method of the heat pump air conditioning system.

[0016] In the embodiments of the present application, the present application determines the current temperature level to which the current exhaust temperature belongs and the current pressure level to which the current exhaust pressure belongs among multiple preset temperature levels and multiple preset pressure levels by acquiring the current exhaust temperature and the current exhaust pressure of the heat pump air conditioning system. According to the current temperature level and the current pressure level, the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to a target opening degree, which can adaptively adjust the electronic expansion valve to a suitable target opening degree in combination with the level of the current exhaust temperature and the current exhaust pressure. Moreover, since the target opening degree is greater than or equal to the first opening degree, and the first opening degree is obtained according to the optimal exhaust pressure of the heat pump air conditioning system, the optimal exhaust pressure is related to the refrigerant temperature on the outlet side of the air cooler, and therefore, for the heat pump air conditioning system in which the optimal exhaust pressure is strongly related to the refrigerant temperature on the outlet side of the air cooler, the target opening degree can meet the demand of the optimal exhaust pressure, which helps the heat pump air conditioning system to operate in a high energy efficiency range and achieve the purpose of energy saving. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0018] FIG. 1 is an implementation flow diagram of a control method of a heat pump air conditioning system according to an embodiment of the present application;

[0019] FIG. 2 is a structural diagram of a heat pump air conditioning system according to an embodiment of the present application;

[0020] FIG. 3 is a specific implementation flow diagram of determining a first opening degree according to an embodiment of the present application;

[0021] FIG. 4 is a specific implementation flow diagram of triggering a protection strategy according to an embodiment of the present application;

[0022] FIG. 5 is a specific implementation flow diagram of controlling the opening degree of an electronic expansion valve according to an embodiment of the present application;

[0023] FIG. 6 is a structural diagram of a control device of a heat pump air conditioning system according to an embodiment of the present application;

[0024] FIG. 7 is a structural diagram of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present application clearer, further detailed description will be given below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0026] Currently, the heat pump air conditioning system needs to control the opening degree of the electronic expansion valve to control the superheat degree at the outlet of the evaporator or the subcooling degree at the outlet of the condenser, so that the entire system runs in a stable and efficient interval.

[0027] However, actual tests have found that some heat pump air conditioning systems may not be able to run in the high-efficiency interval under this control mode. Specifically, the applicant has found that, for a carbon dioxide (CO2) heat pump air conditioning system, due to the characteristics of CO2 itself and the influence of the application environment, the CO2 heat pump air conditioning system runs in a transcritical cycle most of the time. When the CO2 heat pump air conditioning system runs in a transcritical cycle, the current discharge pressure of the compressor has a great influence on the energy efficiency of the entire heat pump air conditioning system. There is an optimal discharge pressure at which the energy efficiency of the heat pump air conditioning system can reach the optimum. And there is a positive correlation between the optimal discharge pressure and the refrigerant temperature at the outlet of the gas cooler. If the electronic expansion valve is controlled according to the subcooling degree or the superheat degree at this time according to the traditional mode, the heat pump air conditioning system may not run in the high-efficiency interval, which results in that the performance of the system cannot be fully utilized. It can be understood that other refrigerants with similar characteristics as CO2 will also cause the CO2 heat pump air conditioning system to have this problem.

[0028] In view of this, the present application proposes a control method of a heat pump air conditioning system, which can make the target opening degree meet the demand of the optimal discharge pressure, help the heat pump air conditioning system to run in a high-energy-efficiency interval, and achieve the purpose of energy saving.

[0029] It should be noted that the embodiments of the present application are completed on the basis of the above-mentioned findings and analysis, and the above-mentioned findings and analysis are not prior art, but should be regarded as part of the contribution of the present application to the prior art.

[0030] In order to illustrate the technical solutions of the present application, specific embodiments will be described below.

[0031] Fig. 1 shows an implementation flowchart of a control method of a heat pump air conditioning system according to an embodiment of the present application. The method can be applied to a heat pump air conditioning system. The heat pump air conditioning system can be configured on a vehicle or other equipment that needs to use a heat pump air conditioning system.

[0032] In the embodiments of the present application, the vehicle can be configured with a heat pump air conditioning system. FIG. 2 shows a schematic diagram of a heat pump air conditioning system of a vehicle according to an embodiment of the present application. The heat pump air conditioning system can include an evaporator, a compressor, an electronic expansion valve, and an air cooler. The refrigerant is compressed isentropically by the compressor, condensed by the air cooler, throttled by the electronic expansion valve, and evaporated isobarically by the evaporator to complete the cycle of the refrigerant. The type of the refrigerant can be selected according to actual conditions. In some embodiments of the present application, the refrigerant can be CO2 (refrigerant code R-744).

[0033] Specifically, the control method of the heat pump air conditioning system can include the following steps S101 to S103.

[0034] In step S101, the current discharge temperature and the current discharge pressure of the heat pump air conditioning system are obtained.

[0035] The current discharge temperature and the current discharge pressure refer to the real-time discharge temperature and the discharge pressure of the compressor in the heat pump air conditioning system, respectively.

[0036] In some embodiments of the present application, the current discharge temperature can be collected in real time by a temperature sensor, and the current discharge pressure can be collected in real time by a pressure sensor. In other embodiments, the current discharge temperature and the current discharge pressure can be estimated by parameters in the internal circulation of the heat pump air conditioning system. The present application does not limit the manner of obtaining the current discharge temperature and the current discharge pressure.

[0037] In step S102, the current temperature level to which the current discharge temperature belongs is determined among a plurality of preset temperature levels, and the current pressure level to which the current discharge pressure belongs is determined among a plurality of preset pressure levels.

[0038] In the embodiments of the present application, the current discharge temperature T out,act and the current discharge pressure P out,act The higher the current discharge temperature and the current discharge pressure, the worse the operating condition of the heat pump air conditioning system. In order to better distinguish different operating conditions, a plurality of preset temperature levels and a plurality of preset pressure levels can be set in advance, so as to determine the current temperature level to which the current discharge temperature belongs among the plurality of preset temperature levels, and determine the current pressure level to which the current discharge pressure belongs among the plurality of preset pressure levels, thereby protecting the heat pump air conditioning system according to the operating condition.

[0039] As an example, Table 1 below shows a plurality of preset temperature levels and their corresponding discharge temperature intervals.

[0040] Table 1

[0041] As an example, Table 2 below shows a plurality of preset pressure levels and their corresponding discharge pressure intervals.

[0042] Table 2

[0043] In step S103, the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to the target opening degree according to the current temperature level and the current pressure level.

[0044] In the embodiments of the present application, the operating condition of the current heat pump air conditioning system can be determined according to the current temperature level and the current pressure level, so that the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to the target opening degree that matches the operating condition.

[0045] It should be emphasized that in the embodiments of the present application, the target opening degree is greater than or equal to the first opening degree. The first opening degree is obtained according to the optimal discharge pressure of the heat pump air conditioning system, and the optimal discharge pressure is related to the refrigerant temperature at the outlet side of the air cooler. The refrigerant temperature at the outlet side of the air cooler can be collected based on a temperature sensor.

[0046] Specifically, the heat pump air conditioning system can obtain the optimal discharge pressure based on the refrigerant temperature at the outlet side of the air cooler. The first opening degree is determined according to the optimal discharge pressure, and then the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to the first opening degree or above according to the current temperature level and the current pressure level. This makes the target opening degree meet the demand of the optimal discharge pressure.

[0047] In the embodiments of the present application, the heat pump air conditioning system obtains the current discharge temperature and the current discharge pressure of the heat pump air conditioning system, determines the current temperature level to which the current discharge temperature belongs and the current pressure level to which the current discharge pressure belongs among a plurality of preset temperature levels and a plurality of preset pressure levels. According to the current temperature level and the current pressure level, the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to the target opening degree, which can adaptively adjust the electronic expansion valve to the appropriate target opening degree in combination with the level of the current discharge temperature and the current discharge pressure. Moreover, since the target opening degree is greater than or equal to the first opening degree, and the first opening degree is obtained according to the optimal discharge pressure of the heat pump air conditioning system, the optimal discharge pressure is related to the refrigerant temperature at the outlet side of the air cooler, for the heat pump air conditioning system whose optimal discharge pressure is strongly related to the refrigerant temperature at the outlet side of the air cooler, the target opening degree can meet the demand of the optimal discharge pressure, which helps the heat pump air conditioning system to operate in the high energy efficiency interval and achieve the energy saving purpose.

[0048] Specifically, please refer to FIG. 3, the calculation process of the first opening degree can include steps S301 to S303.

[0049] In step S301, the optimal discharge pressure is determined according to the refrigerant temperature.

[0050] In which, the optimal discharge pressure Popt The optimal discharge pressure can be positively correlated with the refrigerant temperature.

[0051] In some embodiments of the present application, the optimal discharge pressure calculation formula can be represented as: P opt = K*T gc,out + C offset ;

[0052] wherein P opt is the optimal discharge pressure of the compressor, in MPa; K is a constant coefficient; T gc,out is the refrigerant temperature at the outlet side of the air cooler, in ℃; and C offset is an offset constant, in MPa.

[0053] In some specific embodiments, the constant coefficient K and the offset constant C offset may be determined according to the working mode of the heat pump air conditioning system. Specifically, the working mode of the heat pump air conditioning system can include a refrigeration mode, a heating mode, a dehumidification mode, and a defrosting mode. The corresponding constant coefficient K and the corresponding offset constant C offset for each working mode can be pre-calibrated to form a mapping table. When determining the optimal discharge pressure, the current working mode can be obtained based on the working mode selected by the user or the system, and the constant coefficient K and the offset constant C offset corresponding to the current working mode can be obtained according to the current working mode and the mapping table calibrated.

[0054] Step S302, determining the control parameter for proportional-integral control of the electronic expansion valve according to the optimal discharge pressure.

[0055] Step S303, determining the first opening degree according to the control parameter.

[0056] Proportional-integral control (PI control) is a control strategy combining proportional control and integral control. The proportional control part is used to make the output signal proportional to the deviation of the input signal, quickly respond to system changes, and the integral control part can eliminate steady-state error by integrating the deviation to ensure that the heat pump air conditioning system has no error when reaching steady state. The control parameter of proportional-integral control can be used to adjust the relationship between the input signal and the output signal. The optimal discharge pressure is related to the input signal, and the output signal is the first opening degree of the electronic expansion valve.

[0057] In the embodiments of the present application, the proportional-integral control can adopt a combination strategy of feedforward and PI control, a proportional-integr-Derivative control (PID control) strategy, or a combination strategy of feedforward and proportional-integr-Derivative control (PID control), and the present application does not limit this.

[0058] In order to reduce the operation complexity and calibration difficulty, in some embodiments of the present application, the proportional-integral control can adopt a combination strategy of feedforward and PI control.

[0059] Specifically, the control parameters can include a feedforward value and a control error of the proportional-integral control. According to the optimal exhaust pressure, determining the control parameters of the proportional-integral control of the electronic expansion valve can include: calculating a pressure difference between the current exhaust pressure and the optimal exhaust pressure; calculating a temperature difference between the actual air outlet temperature of the heat pump air conditioning system and the target air outlet temperature of the heat pump air conditioning system; determining the feedforward value according to the ambient temperature and the temperature difference; and determining the control error according to the pressure difference.

[0060] Wherein, the ambient temperature and the actual air outlet temperature can be collected by a temperature sensor, and the target air outlet temperature can be set according to the comfort requirement of the vehicle environment. The feedforward value EXV pre is negatively correlated with the ambient temperature T amb , and is positively correlated with the temperature difference T airout,err .

[0061] Specifically, after calculating the pressure difference P out，act between the current exhaust pressure P opt of the compressor and the optimal exhaust pressure P err , and the temperature difference T airout,act between the actual air outlet temperature T airout,tar and the target air outlet temperature T airout,err , the feedforward value EXV amb of the PI controller can be obtained according to the ambient temperature T airout,err and the temperature difference T pre , and the pressure difference P err is taken as the control error of the PI controller.

[0062] In some embodiments of the present application, the first opening degree of the electronic expansion valve can be represented as:

[0063] Wherein, EXV cal represents the first opening degree; EXV pre represents the feedforward value; K p represents the proportional term coefficient; Perr (t) represents a pressure difference; K i represents an integral term coefficient.

[0064] In some specific embodiments, the proportional term coefficient K p and the integral term coefficient K i may be determined according to the working mode of the heat pump air conditioning system. Each working mode can be pre-calibrated to correspond to a proportional term coefficient K p and a corresponding integral term coefficient K i to form a mapping table. When determining the first opening degree, the proportional term coefficient K p and the integral term coefficient K i corresponding to the current working mode can be obtained according to the current working mode and the mapping table obtained by calibration.

[0065] For the calibration process of the proportional term coefficient K p and the integral term coefficient K i , the influence of different proportional term coefficients K p and integral term coefficients K i on the exhaust pressure can be tested while the target evaporating temperature of the strongly controlled heat pump air conditioning system is unchanged. A suitable value can be selected so that the exhaust pressure does not appear to be significantly shaken and the response speed can meet the system regulation requirements.

[0066] Correspondingly, in some embodiments of the present application, when adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree, ramp processing and anti-shake processing can be performed. The ramp processing can be used to control the change speed of the opening degree, and the anti-shake processing can be used to control the number of changes of the opening degree.

[0067] In some embodiments of the present application, after determining the current temperature level to which the current exhaust temperature belongs and the current pressure level to which the current exhaust pressure belongs, different protection strategies can be triggered in stages, and the heat pump air conditioning system can be controlled according to the corresponding protection strategies, so that the heat pump air conditioning system operates in a high energy efficiency interval.

[0068] Protection strategy 1: In some embodiments of the present application, the above-mentioned multiple preset temperature levels can include a first temperature level, and the multiple preset pressure levels can include a first pressure level. At this time, according to the current temperature level and the current pressure level, adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree can include: if the current temperature level is the first temperature level and the current pressure level is the first pressure level, adjusting the opening degree of the electronic expansion valve to the first opening degree.

[0069] The first temperature level and the first pressure level can represent the lowest preset temperature level and the lowest preset pressure level, corresponding to the optimal working condition of the heat pump air conditioning system. When the current temperature level is the first temperature level T protc Level0 and the current pressure level is the first pressure level P protc Level0, the protection strategy 1 can be triggered. At this time, the first opening degree can be calculated, the first opening degree is taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree.

[0070] The calculation process of the first opening degree can refer to the description of FIG. 3, which will not be repeated here.

[0071] Correspondingly, in some embodiments of the present application, adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree according to the current temperature level and the current pressure level can further include: if the current temperature level exceeds the first temperature level, or the current pressure level exceeds the first pressure level, determining a minimum opening degree of the electronic expansion valve according to the current rotating speed of the compressor of the heat pump air conditioning system; taking the maximum value between the minimum opening degree and the first opening degree as the target opening degree, and adjusting the opening degree of the electronic expansion valve to the target opening degree.

[0072] The current rotating speed of the compressor and the minimum opening degree of the electronic expansion valve are positively correlated. The minimum opening degree is used to limit the lower limit of the opening degree, which can ensure that the exhaust pressure and the exhaust temperature can be maintained in a suitable range after the opening degree of the electronic expansion valve is adjusted to the target opening degree, so that the heat pump air conditioning system can operate in the high-efficiency range.

[0073] Specifically, the case that the current temperature level exceeds the first temperature level, or the current pressure level exceeds the first pressure level can be divided into three different protection strategies.

[0074] Protection strategy 2: in some embodiments of the present application, the above-mentioned multiple preset temperature levels can include a second temperature level, and the multiple preset pressure levels include a second pressure level. At this time, adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree according to the current temperature level and the current pressure level can include: if the current temperature level is the second temperature level, or the current pressure level is the second pressure level, determining a minimum opening degree of the electronic expansion valve according to the current rotating speed of the compressor of the heat pump air conditioning system; taking the maximum value between the minimum opening degree and the first opening degree as the target opening degree, and adjusting the opening degree of the electronic expansion valve to the target opening degree.

[0075] The second temperature level and the second pressure level can represent the second-lowest preset temperature level and the second-lowest preset pressure level, corresponding to the suboptimal working condition of the heat pump air conditioning system. When the current temperature level is the second temperature level T protcLevel 1 or the current pressure level is the second pressure level P protc At Level 1, protection strategy 2 can be triggered. At this time, the first minimum opening degree EXVprotcLevel1 corresponding to the current rotating speed of the compressor can be obtained based on a lookup table. The first minimum opening degree corresponding to the current rotating speed of different compressors is different. The maximum value between the first opening degree and the first minimum opening degree can be taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree.

[0076] The calculation process of the first opening degree can refer to the description of FIG. 3, and will not be described here.

[0077] In some embodiments of the present application, the control method of the heat pump air conditioning system can further include: if the current temperature level exceeds the second temperature level, or the current pressure level exceeds the second pressure level, the rotating speed of the compressor is controlled at a preset rotating speed reduction rate.

[0078] That is, if the current temperature level exceeds the second temperature level, or the current pressure level exceeds the second pressure level, the opening degree of the electronic expansion valve is adjusted to the target opening degree, and the rotating speed of the compressor is controlled at a preset rotating speed reduction rate at the same time, which can make the heat pump air conditioning system return to the high efficiency interval faster.

[0079] Specifically, the case that the current temperature level exceeds the second temperature level, or the current pressure level exceeds the second pressure level can be divided into two different protection strategies.

[0080] The plurality of preset temperature levels can further include a third temperature level higher than the second temperature level and a fourth temperature level higher than the third temperature level, and the plurality of preset pressure levels can further include a third pressure level higher than the second pressure level and a fourth pressure level higher than the third pressure level.

[0081] Protection strategy 3: adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree according to the current temperature level and the current pressure level can include: if the current temperature level is the third temperature level, or the current pressure level is the third pressure level, determining the minimum opening degree of the electronic expansion valve according to the current rotating speed of the compressor of the heat pump air conditioning system; taking the maximum value between the minimum opening degree and the first opening degree as the target opening degree, and adjusting the opening degree of the electronic expansion valve to the target opening degree. And the rotating speed of the compressor is controlled at a preset rotating speed reduction rate, which includes: if the current temperature level is the third temperature level, or the current pressure level is the third pressure level, the rotating speed of the compressor is controlled at a first rotating speed reduction rate.

[0082] The protection strategy 4: according to the current temperature level and the current pressure level, the opening degree of the electronic expansion valve of the heat pump air conditioning system is adjusted to the target opening degree, which can include: if the current temperature level is the fourth temperature level, or the current pressure level is the fourth pressure level, the minimum opening degree of the electronic expansion valve is determined according to the current rotating speed of the compressor of the heat pump air conditioning system; the maximum value between the minimum opening degree and the first opening degree is taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree. And the compressor is controlled at a preset rotating speed reduction rate, including: if the current temperature level is the fourth temperature level, or the current pressure level is the fourth pressure level, the compressor is controlled at a second rotating speed reduction rate.

[0083] The second rotating speed reduction rate can be higher than the first rotating speed reduction rate.

[0084] That is, when the rotating speed reduction control is performed, the rotating speed reduction process can be performed in stages according to the current exhaust pressure and the current exhaust temperature.

[0085] When the current temperature level is the third temperature level TprotcLevel2 or the current pressure level is the third pressure level PprotcLevel2, the protection strategy 3 is triggered. At this time, based on the current rotating speed of the compressor, the second minimum opening degree EXVprotcLevel2 can be obtained by looking up the table, and the second minimum opening degree corresponding to the current rotating speed of different compressors is different. The maximum value between the first opening degree and the second minimum opening degree can be taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree. At the same time, the compressor can be controlled at a first rotating speed reduction rate. The calculation process of the first opening degree can refer to the description of FIG. 3, and will not be repeated here. The first rotating speed reduction rate can be set according to actual conditions, for example, set to 50 rpm / s.

[0086] When the current temperature level is the fourth temperature level TprotcLevel3 or the current pressure level is the fourth pressure level PprotcLevel3, the protection strategy 4 is triggered. At this time, based on the current rotating speed of the compressor, the second minimum opening degree EXVprotcLevel2 can be obtained by looking up the table, and the third minimum opening degree corresponding to the current rotating speed of different compressors is different. The maximum value between the first opening degree and the third minimum opening degree can be taken as the target opening degree, and the opening degree of the electronic expansion valve is adjusted to the target opening degree. At the same time, the compressor can be controlled at a second rotating speed reduction rate. The calculation process of the first opening degree can refer to the description of FIG. 3, and will not be repeated here. The second rotating speed reduction rate can be set according to actual conditions, for example, set to 100 rpm / s.

[0087] It should be noted that the correspondence between the current speed of the compressor and the first minimum opening degree, the current speed of the compressor and the second minimum opening degree, and the current speed of the compressor and the third minimum opening degree can be the same or different. When the correspondence is different, the first minimum opening degree at the same speed is less than the second minimum opening degree, and the second minimum opening degree is less than the third minimum opening degree.

[0088] In addition, a protection strategy 5 can also be set: the plurality of preset temperature levels can further include a fifth temperature level, and the plurality of preset pressure levels can further include a fifth pressure level. At this time, the control method of the heat pump air conditioning system can further include: when the current temperature level is the fifth temperature level or the current pressure level is the fifth pressure level, the electronic expansion valve is controlled according to the maximum opening degree of the electronic expansion valve, and the speed of the compressor is reduced to 0.

[0089] Among them, the fifth temperature level and the fifth pressure level can represent the highest preset temperature level and the highest preset pressure level, corresponding to the worst case of the heat pump air conditioning system working condition.

[0090] Specifically, the duration of the exhaust temperature protection level being the fifth temperature level TprotcLevel4 or the exhaust pressure protection level being the fifth pressure level PprotcLevel4 can be recorded. If the duration is greater than the duration threshold, the electronic expansion valve is controlled according to the maximum opening degree of the electronic expansion valve, and the speed of the compressor is reduced to 0, so that the heat pump air conditioning system is stopped and balanced.

[0091] Among them, the duration threshold can be set according to the actual situation, for example, 10s.

[0092] Correspondingly, after the heat pump air conditioning system is balanced, the compressor can be restarted to make the heat pump air conditioning system run normally. Among them, the balance of the heat pump air conditioning system can mean that the difference between the exhaust pressure and the suction pressure is less than the difference threshold. In this way, the heat pump air conditioning system can be stopped to restore normal operation of the heat pump air conditioning system.

[0093] Please refer to the heat pump air conditioning system protection strategy triggering process shown in FIG. 4, Table 1 and Table 2. In some embodiments of the present application, it can be determined in turn whether the current temperature level and the current pressure level can meet the protection strategy 5, the protection strategy 4, the protection strategy 3, the protection strategy 2 and the protection strategy 1, until any one of the protection strategies is triggered. The control method of each protection strategy can be referred to the foregoing description, which will not be repeated here.

[0094] Please refer to FIG. 5, which shows a control flow of the electronic expansion valve. The vehicle can obtain the current working mode based on the user operation or the working mode selected by the heat pump air conditioning system. If the current working mode is the stop mode or the ventilation mode, stop the opening degree control. If the current working mode is the refrigeration mode, the heating mode, the dehumidification mode or the defrosting mode, obtain the constant coefficient K corresponding to the current working mode and the offset constant C corresponding to the current working mode according to the current working mode offset , so as to determine the optimal discharge pressure according to the refrigerant temperature at the outlet side of the air cooler, calculate the pressure difference between the current discharge pressure and the optimal discharge pressure, and the temperature difference between the actual air outlet temperature and the target air outlet temperature. Then, determine the feedforward value according to the temperature difference between the actual air outlet temperature and the target air outlet temperature and the ambient temperature, take the pressure difference as the control error, calculate the first opening degree according to the proportional term coefficient K p and the integral term coefficient K i corresponding to the current working mode, then determine the target opening degree according to the current pressure level and the current temperature level, and then perform slope processing and anti-shake processing to control the electronic expansion valve to adjust to the corresponding opening degree.

[0095] In the embodiments of the present application, for the heat pump air conditioning system whose optimal discharge pressure is strongly related to the refrigerant temperature at the outlet side of the air cooler, the target opening degree can meet the demand of the optimal discharge pressure, which helps the heat pump air conditioning system to operate in the high energy efficiency interval and achieve the purpose of energy saving. Moreover, in the high load condition, due to the operating characteristics of the CO2 refrigerant and the CO2 heat pump system, the discharge pressure and the discharge temperature are too high, which easily triggers the compressor protection and frequent shutdown, affecting the user comfort and the service life of the compressor. However, by using the hierarchical triggering protection strategy, the heat pump air conditioning system can exert its maximum performance without easily triggering the shutdown protection, which can guarantee the user comfort.

[0096] As shown in FIG. 6, the heat pump air conditioning system control device 600 provided in the embodiments of the present application is configured in the vehicle.

[0097] Specifically, the heat pump air conditioning system control device 600 can include:

[0098] The acquisition unit 601 is configured to acquire the current discharge temperature and the current discharge pressure of the heat pump air conditioning system.

[0099] The hierarchical unit 602 is configured to determine the current temperature level to which the current discharge temperature belongs among a plurality of preset temperature levels, and determine the current pressure level to which the current discharge pressure belongs among a plurality of preset pressure levels.

[0100] The control unit 603 is configured to adjust the opening degree of the electronic expansion valve of the heat pump air conditioning system to a target opening degree according to the current temperature level and the current pressure level, the target opening degree being greater than or equal to a first opening degree, the first opening degree being obtained according to an optimal discharge pressure of the heat pump air conditioning system, the optimal discharge pressure being related to the refrigerant temperature on the outlet side of the air cooler.

[0101] In some embodiments of the present application, the control unit 603 can be further configured to determine the optimal discharge pressure according to the refrigerant temperature, determine a control parameter for proportional-integral control of the electronic expansion valve according to the optimal discharge pressure, and determine the first opening degree according to the control parameter.

[0102] In some embodiments of the present application, the control parameter includes a feedforward value and a control error of the proportional-integral control, and the control unit 603 can be further configured to calculate a pressure difference between the current discharge pressure and the optimal discharge pressure, calculate a temperature difference between an actual outlet air temperature of the heat pump air conditioning system and a target outlet air temperature of the heat pump air conditioning system, determine the feedforward value according to the ambient temperature and the temperature difference, and determine the control error according to the pressure difference.

[0103] In some embodiments of the present application, the plurality of preset temperature levels includes a first temperature level, and the plurality of preset pressure levels includes a first pressure level, and the control unit 603 can be configured to adjust the opening degree of the electronic expansion valve to the first opening degree if the current temperature level is the first temperature level and the current pressure level is the first pressure level, and adjust the opening degree of the electronic expansion valve to a target opening degree according to a current rotating speed of the compressor of the heat pump air conditioning system if the current temperature level exceeds the first temperature level or the current pressure level exceeds the first pressure level, the target opening degree being a maximum value between the first opening degree and a minimum opening degree of the electronic expansion valve.

[0104] In some embodiments of the present application, the plurality of preset temperature levels further includes a second temperature level higher than the first temperature level, and the plurality of preset pressure levels further includes a second pressure level higher than the first pressure level, and the control unit 603 can be configured to perform a rotating speed reduction control on the compressor according to a preset rotating speed reduction rate if the current temperature level exceeds the second temperature level or the current pressure level exceeds the second pressure level.

[0105] In some embodiments of the present application, the plurality of preset temperature levels further comprises a third temperature level higher than the second temperature level and a fourth temperature level higher than the third temperature level, and the plurality of preset pressure levels further comprises a third pressure level higher than the second pressure level and a fourth pressure level higher than the third pressure level; the control unit 603 can be specifically configured to: if the current temperature level is the third temperature level or the current pressure level is the third pressure level, the compressor is controlled at the first speed reduction rate; if the current temperature level is the fourth temperature level or the current pressure level is the fourth pressure level, the compressor is controlled at the second speed reduction rate, and the second speed reduction rate is higher than the first speed reduction rate.

[0106] In some embodiments of the present application, the plurality of preset temperature levels comprises a fifth temperature level, and the plurality of preset pressure levels comprises a fifth pressure level; the control unit 603 can be specifically configured to: when the current temperature level is the fifth temperature level or the current pressure level is the fifth pressure level, the electronic expansion valve is controlled at the maximum opening degree, and the speed of the compressor is reduced to 0.

[0107] It should be noted that, for the convenience and brevity of description, the specific working process of the control device 600 of the heat pump air conditioning system described above can refer to the corresponding process of the method of FIGS. 1 to 5, which will not be described here.

[0108] As shown in FIG. 7, a schematic diagram of a vehicle provided by an embodiment of the present application is shown. Specifically, the vehicle 7 can include a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and executable on the processor 70, such as a heat pump air conditioning system control program, and a heat pump air conditioning system 73.

[0109] The processor 70 implements the steps in the above-mentioned various heat pump air conditioning system control method embodiments when executing the computer program 72, such as steps S101 to S103 shown in FIG. 1. Alternatively, the processor 70 implements the functions of the modules / units in the above-mentioned various device embodiments when executing the computer program 72, such as the functions of the acquisition unit 601, the grading unit 602, and the control unit 603 shown in FIG. 6.

[0110] The computer program can be divided into one or more modules / units, which are stored in the memory 71 and executed by the processor 70 to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the vehicle.

[0111] For example, the computer program can be divided into: an acquisition unit, a grading unit and a control unit. The specific functions of each unit are as follows: the acquisition unit is configured to acquire a current exhaust temperature and a current exhaust pressure of the heat pump air conditioning system; the grading unit is configured to determine a current temperature grade to which the current exhaust temperature belongs among a plurality of preset temperature grades, and determine a current pressure grade to which the current exhaust pressure belongs among a plurality of preset pressure grades; and the control unit is configured to adjust an opening degree of an electronic expansion valve of the heat pump air conditioning system to a target opening degree according to the current temperature grade and the current pressure grade, the target opening degree being greater than or equal to a first opening degree, the first opening degree being obtained according to an optimal exhaust pressure of the heat pump air conditioning system, the optimal exhaust pressure being related to a refrigerant temperature on an outlet side of an air cooler.

[0112] The vehicle can include, but is not limited to, a processor 70, a memory 71. Those skilled in the art can understand that FIG. 7 is only an example of the vehicle and does not constitute a limitation on the vehicle, and can include more or fewer components than those shown, or combine certain components, or different components, for example, the vehicle can also include an input / output device, a network access device, a bus, etc.

[0113] The processor 70 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), ready programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0114] The memory 71 can be an internal storage unit of the vehicle, such as a hard disk or a memory of the vehicle. The memory 71 can also be an external storage device of the vehicle, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 71 can include both the internal storage unit and the external storage device of the vehicle. The memory 71 is used to store the computer program and other programs and data required by the vehicle. The memory 71 can also be used to temporarily store data that has been output or will be output.

[0115] It should be noted that, for the convenience and brevity of description, the structure of the vehicle described above can also refer to the specific description of the structure in the method embodiments, which will not be described here.

[0116] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be realized in the form of hardware or software function unit. In addition, the specific name of each functional unit and module is only for the convenience of mutual distinction, and does not limit the protection scope of the present application. The specific working process of the unit and module in the above system can refer to the corresponding process in the foregoing method embodiment, which will not be described here.

[0117] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0118] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0119] In the embodiments provided in the present application, it should be understood that the disclosed devices / vehicles and methods can be implemented in other ways. For example, the device / vehicle embodiments described above are only schematic. For example, the division of the module or unit is only a logical function division, and actual implementation can have another division manner. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed mutual units can be indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0120] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0121] In addition, each of the function units in each of the embodiments of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0122] If the integrated module / unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. When the processor executes the computer program, the steps of each method embodiment described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0123] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control method of a heat pump air conditioning system, characterized by, The method comprises: obtaining a current exhaust temperature and a current exhaust pressure of the heat pump air conditioning system; determining a current temperature level to which the current exhaust temperature belongs among a plurality of preset temperature levels, and determining a current pressure level to which the current exhaust pressure belongs among a plurality of preset pressure levels; adjusting an opening degree of an electronic expansion valve of the heat pump air conditioning system to a target opening degree according to the current temperature level and the current pressure level, the target opening degree being greater than or equal to a first opening degree, the first opening degree being obtained according to an optimal exhaust pressure of the heat pump air conditioning system, the optimal exhaust pressure being related to a refrigerant temperature at an outlet side of an air cooler.

2. The control method of a heat pump air conditioning system according to claim 1, characterized by, The control method of the heat pump air conditioning system further comprises: determining the optimal exhaust pressure according to the refrigerant temperature; determining a control parameter for proportional-integral control of the electronic expansion valve according to the optimal exhaust pressure; determining the first opening degree according to the control parameter.

3. The control method of a heat pump air conditioning system according to claim 2, characterized by, The control method of the heat pump air conditioning system further comprises: obtaining a current working mode based on a user operation or a working mode selected by the heat pump air conditioning system; stopping the opening degree control of the electronic expansion valve if the current working mode is a shutdown mode or a ventilation mode; performing the step of determining the optimal exhaust pressure according to the refrigerant temperature if the current working mode is a refrigeration mode, a heating mode, a dehumidification mode or a defrosting mode.

4. The control method of a heat pump air conditioning system according to claim 2, characterized by, The step of determining the optimal exhaust pressure according to the refrigerant temperature comprises: determining the optimal exhaust pressure based on the following formula: P opt = K * T gc，out + C offset ; Wherein, P opt is the optimal exhaust pressure; K is a constant coefficient; T gc，out is the refrigerant temperature; C offset is a shift constant.

5. The control method of a heat pump air conditioning system according to claim 4, characterized by, The method further comprises: determining a mode in a mapping table that matches the current working mode of the heat pump air conditioning system; determining a constant coefficient and an offset constant corresponding to the mode in the mapping table as the constant coefficient and the offset constant.

6. The control method of a heat pump air conditioning system according to claim 2, wherein The control parameter comprises a feedforward value and a control error of proportional-integral control; and the step of determining the control parameter for proportional-integral control of the electronic expansion valve according to the optimal exhaust pressure comprises: calculating a pressure difference between the current exhaust pressure and the optimal exhaust pressure; calculating a temperature difference between an actual air outlet temperature of the heat pump air conditioning system and a target air outlet temperature of the heat pump air conditioning system; determining the feedforward value according to an ambient temperature and the temperature difference; determining the control error according to the pressure difference.

7. The control method of a heat pump air conditioning system according to claim 6, wherein The step of determining the first opening degree according to the control parameter comprises: determining the first opening degree based on the following equation; where EXV cal represents the first opening degree; EXV pre represents a feedforward value in the control parameter; K p represents a proportional term coefficient; P err (t) represents a pressure difference in the control parameter; K i represents an integral term coefficient.

8. The control method of a heat pump air conditioning system according to claim 7, characterized by, The proportional term coefficient and the integral term coefficient are obtained according to a working mode of the heat pump air conditioning system and a pre-labeled mapping table, and each working mode in the mapping table has a corresponding proportional term coefficient and a corresponding integral term coefficient.

9. The control method of a heat pump air conditioning system according to claim 6, wherein, The ambient temperature and the actual air outlet temperature can be collected by a temperature sensor, and the target air outlet temperature is determined according to a comfort requirement of a vehicle riding environment.

10. The control method of a heat pump air conditioning system according to claim 1, characterized by, The plurality of preset temperature levels comprise a first temperature level, and the plurality of preset pressure levels comprise a first pressure level; The step of adjusting the opening degree of the electronic expansion valve of the heat pump air conditioning system to the target opening degree according to the current temperature level and the current pressure level comprises: if the current temperature level is the first temperature level and the current pressure level is the first pressure level, adjusting the opening degree of the electronic expansion valve to the first opening degree; if the current temperature level exceeds the first temperature level or the current pressure level exceeds the first pressure level, determining a minimum opening degree of the electronic expansion valve according to a current rotating speed of a compressor of the heat pump air conditioning system, and adjusting the opening degree of the electronic expansion valve to a maximum value between the minimum opening degree and the first opening degree.

11. The control method of a heat pump air conditioning system according to claim 10, characterized by, The plurality of preset temperature levels further comprises a second temperature level higher than the first temperature level, and the plurality of preset pressure levels further comprises a second pressure level higher than the first pressure level. The control method of the heat pump air conditioning system further comprises: if the current temperature level exceeds the second temperature level or the current pressure level exceeds the second pressure level, performing rotating speed reduction control on the compressor according to a preset rotating speed reduction rate.

12. The control method of a heat pump air conditioning system according to claim 11, wherein, The plurality of preset temperature levels further comprises a third temperature level higher than the second temperature level and a fourth temperature level higher than the third temperature level, and the plurality of preset pressure levels further comprises a third pressure level higher than the second pressure level and a fourth pressure level higher than the third pressure level. The performing rotating speed reduction control on the compressor according to a preset rotating speed reduction rate comprises: if the current temperature level is the third temperature level or the current pressure level is the third pressure level, performing rotating speed reduction control on the compressor according to a first rotating speed reduction rate; if the current temperature level is the fourth temperature level or the current pressure level is the fourth pressure level, performing rotating speed reduction control on the compressor according to a second rotating speed reduction rate, the second rotating speed reduction rate being higher than the first rotating speed reduction rate.

13. The control method of a heat pump air conditioning system according to any one of claims 1 to 12, characterized in that, The plurality of preset temperature levels comprises a fifth temperature level, and the plurality of preset pressure levels comprises a fifth pressure level; the control method of the heat pump air conditioning system further comprises: if the current temperature level is the fifth temperature level or the current pressure level is the fifth pressure level, performing control on the electronic expansion valve according to a maximum opening degree of the electronic expansion valve, and reducing the rotating speed of the compressor to 0.

14. A computer-readable storage medium, the computer-readable storage medium storing a computer program, characterized in that, The computer program, when executed by a processor, implements the steps of the control method of the heat pump air conditioning system according to any one of claims 1 to 13.

15. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The vehicle comprises a heat pump air conditioning system, and the processor executes the computer program to implement the steps of the control method of the heat pump air conditioning system according to any one of claims 1 to 13.

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